The present invention relates to improvements to tooth-pastes.
It is well known that, in dental hygiene, the brushing time of the teeth is a particularly important factor. This brushing time is generally difficult to appreciate and, until now, no efficient and practical solution has been proposed for solving this problem. Actually, efforts have been made (Chemical Abstracts vol. 82 No 8, Apr. 21, 1975, page 349, Summary No 103032j) to solve this problem by incorporating into the tooth-pasge a natural pigment absorbed by absorbants such as cellulose, so as to obtain an indication relative to the efficient cleaning of the teeth via a modification of color. The same concern is also shown in "Chemical Abstracts vol. 104, No 4, January 1986, page 290, Summary No 24979z" which discloses a tooth-paste composition exhibiting a change of color during the application, which includes a coloring agent and a reducing agent. Experience shows that none of the prior techniques allows, on the one hand, obtaining a good initial coloration of the tooth-paste and, on the other hand, a pure decoloration of the tooth-paste after an efficient brushing time, generally evaluated to about 3 minutes. The present invention aims at providing a new tooth-paste composition allowing the user to know with sufficient precision the minimum brushing time necessary for an efficient brushing.